Myofibromatosis in adults, glomangiopericytoma, and myopericytoma: a spectrum of tumors showing perivascular myoid differentiation

Myopericytoma of the axillary artery in a 4-year-old girl presenting with stroke and subsequent progression of micro-isolated lesion

A 4-year-old girl presented with complaints of transient speech disorder and left-sided weakness. Magnetic resonance imaging revealed multiple strokes, computed tomography showed a right axillary artery aneurysm of 40 mm, and an angiogram indicated retrograde embolism. She underwent aneurysm resection and reconstruction with a saphenous vein graft. Two years after surgery, a mass lesion occurred in the native artery on the proximal side of the prior surgical anastomosis. Surgical resection and reconstruction were performed. An isolated 1-mm diameter lesion was found in the retrospectively reviewed completion angiogram from the initial surgery, which was the origin of the subsequent progressive lesion. The pathological examination, including after the initial surgery, revealed a myopericytoma.

Large congenital myopericytoma of the lower eyelid

Congenital fibrous soft tissue tumors in the eyelids are exceptionally rare, with only seven cases of neonatal myofibromas reported. Myopericytoma, a variant with pericytic differentiation, has not previously been described in neonatal eyelid tumors. This report details a case of a massive congenital myopericytoma in a newborn's lower eyelid. The lesion had a broad area of adhesion to the anterior lamella of the lid. After resection, when the child was 11 days old, the resulting defect was successfully reconstructed with a V-Y type perforator-based flap.

Renal myopericytoma: A case report with a literature review

Myopericytoma is a rare soft tissue tumor characterized by differentiation into perivascular muscle-like cells or perimuscular cells. This tumor primarily affects adults and is uncommon in children. It is predominantly found in the subcutaneous soft tissues of the distal limbs, and cases originating in the kidney are exceedingly rare. In this report, we present a case of a patient with renal myopericytoma admitted to our hospital. We also summarize the diagnostic and therapeutic features by reviewing relevant domestic and international literature.

Malignant myopericytoma originating from the colon: A case report

BACKGROUND

Myopericytoma is a benign tumor that typically occurs within subcutaneous tissue and most often involves the distal extremities, followed by the proximal extremities, neck, thoracic vertebrae and oral cavity. Complete resection is often curative. Malignant myopericytoma is extremely rare and has a poor prognosis. Here, we report for the first time a case of malignant myopericytoma originating from the colon.

CASE SUMMARY

A 69-year-old male was admitted to our hospital with right upper quadrant pain for five days. Imaging suggested a liver mass with hemorrhage. A malignant hepatic tumor was the initial diagnosis. Surgical resection was performed after a complete preoperative work up. Initial postoperative pathology suggested that the mass was a malignant myoblastoma unrelated to the liver. Four months after the first surgery, an enhanced computed tomography (CT) scan revealed a recurrence of the tumor. The diagnosis of malignant myopericytoma derived from the colon was confirmed on histopathological examination of the specimen from the second surgery. The patient did not return to the hospital regularly for surveillance. The first postoperative abdominal CT examination six months after the second surgery demonstrated multiple liver metastases. Survival time between the diagnosis of the tumor to death was approximately one year.

CONCLUSION

Malignant myopericytoma is a rare cancer. Preoperative diagnosis may be difficult. Due to a lack of treatment options, prognosis is poor.

Myopericytoma of the Right Middle Finger: A Case Report of an Uncommon Perivascular Neoplasm

This report describes the case of a 29-year-old male who presented with painless swelling on the volar aspect of his right middle finger. The initial clinical impression was consistent with an epidermal inclusion cyst. A plain radiograph of the lesion revealed a circumscribed superficial nodular soft tissue mass confined to the dermis of the affected finger. Following surgical excision and subsequent histopathologic examination, the lesion was ultimately identified as a myopericytoma (MPC). The occurrence of MPCs in the finger is uncommon; thus, a high level of suspicion is required to consider it as one of the differential diagnoses for painless nodules in this anatomical location. Surgery serves as the primary method for treatment, and histopathologic evaluation plays a crucial role in confirming the diagnosis and ruling out malignancy.

Orbital glomangiopericytoma in a 5-year-old child

A 5-year-old girl presented with a 6-month history of strabismus and painless left proptosis. Magnetic resonance imaging revealed a homogenously enhancing, anterior, superomedial, left orbital mass. Excisional biopsy established the diagnosis of orbital glomangiopericytoma. Glomangiopericytoma of soft tissue is a perivascular myoid neoplasm with hemangiocytoma-like vascular channels that has overlapping features between glomus tumor and myopericytoma. To the authors' knowledge, glomangiopericytoma of the orbit has not previously been reported.

A Rare Tumor of Intravascular Myopericytoma in the Right Renal Vein

Myopericytoma, a perivascular myoid neoplasm, is commonly found in the dermis or subcutaneous tissues; however, its occurrence in visceral organs is unusual. Here, we present an extremely rare tumor of intravascular myopericytoma of the right renal vein. A 44-year-old man was incidentally diagnosed with a mass in the right kidney during a routine checkup. A nephrectomy was performed because the urologist suspected renal cancer. A gross examination of the resected specimen revealed a well-circumscribed brown mass in the renal hilum. Histologically, the tumor showed a concentric multilayered proliferation of spindle cells surrounding blood vessels. Immunohistochemical staining showed that the spindle-shaped tumor cells were negative for desmin but positive for α-smooth muscle actin and h-caldesmon, indicating their myoid nature. We confirmed that the tumor was located in the right renal vein because it was encased within a thick wall that was desmin-positive and contained elastic fibers, as shown by Elastica van Gieson staining. The patient was diagnosed with an intravascular myopericytoma of the right renal vein. There are several differential diagnoses for renal mesenchymal tumors, including angiomyolipoma. This emphasizes the importance of considering these uncommon tumors when examining nephrectomy specimens.

Pediatric upper lip myopericytoma: a case report and comprehensive review

BACKGROUND

Myopericytoma is a rare spindle cell tumor of mesenchymal origin, typically benign, characterized by concentric proliferation of tumor cells around blood vessels within subcutaneous tissue. It primarily occurs in middle-aged adults and is often located in distal extremities, although cases have been reported in proximal extremities and head-neck regions. However, occurrences within the oral cavity are exceedingly rare. To date, literature reviews have identified only two cases in children under 10 years old and reported only five cases of myopericytoma occurring in the lip region. We provide a comprehensive review and analysis of all documented cases to better understand this condition.

CASE PRESENTATION

A 7-year-old girl presented to oral and maxillofacial surgery with the discovery of a painless mass on the inner aspect of the upper lip. The diagnosis of myopericytoma was confirmed by histological examination (HE staining), alcian blue staining, and immunohistochemistry.

CONCLUSIONS

Following surgical excision, there were no signs of recurrence at a 3-month follow-up. The pathological diagnosis of myopericytoma is quite challenging, and immunohistochemical testing is necessary.

Misdiagnosis of synovial sarcoma - cellular myofibroma with SRF-RELA gene fusion: A case report

BACKGROUND

Cellular myofibroma is a rare subtype of myofibroma that was first described in 2017. Its diagnosis is often challenging because of its relative rarity, lack of known genetic abnormalities, and expression of muscle markers that can be confused with sarcomas that have myogenic differentiation. Currently, scholars have limited knowledge of this disease, and published cases are few. Further accumulation of diagnostic and treatment experiences is required.

CASE SUMMARY

A 16-year-old girl experienced left upper limb swelling for 3 years. She sought medical attention at a local hospital 10 months ago, where magnetic resonance imaging revealed a 5-cm soft tissue mass. Needle biopsy performed at a local hospital resulted in the diagnosis of a spindle cell soft tissue sarcoma. The patient was referred to our hospital for limb salvage surgery with endoprosthetic replacement. She was initially diagnosed with a synovial sarcoma. Consequently, clinical management with chemotherapy was continued for the malignant sarcoma. Our pathology department also performed fluorescence in situ hybridization for result validation, which returned negative for SS18 gene breaks, indicating that it was not a synovial sarcoma. Next-generation sequencing was used to identify the SRF-RELA rearrangement. The final pathological diagnosis was a cellular/myofibroblastic neoplasm with an SRF-RELA gene fusion. The patient had initially received two courses of chemotherapy; however, chemotherapy was discontinued after the final diagnosis.

CONCLUSION

This case was misdiagnosed because of its rare occurrence, benign biological behavior, and pathological similarity to soft tissue sarcoma.

Myopericytoma of the patella with local recurrence and patellectomy: A case report

INTRODUCTION AND IMPORTANCE

Myopericytomas are tumors originating from perivascular myoid cells and exhibiting a wide range of histologic growth patterns. They rarely occur in bones, and no case of myopericytoma in the patella has been reported so far.

CASE PRESENTATION

A 74-year-old male presented with a chief complaint of pain in the left knee. Magnetic resonance imaging revealed bone tumor and osteolytic lesions of the patella. The patient underwent bone tumor curettage and filling of the cavity with artificial bone. However, as the tumor reoccurred, a patellectomy was performed. The patient regained premorbid functional status after surgery. Additionally, there was no radiological evidence of recurrence of the lesion 3 years after patellectomy.

CLINICAL DISCUSSION

Myopericytoma of the patella is very rare. However, it should be considered for the differential diagnosis of lytic lesions of the bone. Although surgery is curative, patellectomy may be necessary for recurrent cases.

CONCLUSION

In conclusion, we report the first case of patellar myopericytoma. Although patellar myopericytoma might be rare, it should be considered for the differential diagnosis of lytic lesions of the bone. Surgery is curative; however, patellectomy may be necessary in recurrent cases.

Pericytic Lesions: A Paradigm of Overlapping Features

Although myopericytoma and glomangiopericytoma are considered the subtypes of the group myopericytomas (MPC), they differ morphologically. Both of the tumors arise from pericytic cells. Scalp MPC are infrequent, but extranasal glomangiopericytomas are extremely rare. Herein, we report a case of a 36-year-old female presenting with slowly growing scalp swelling. Histopathology showed a dermal tumor with features of myopericytoma as well as glomangiopericytoma within the same lesion. Immunohistochemistry and reticulin staining confirmed pericytic origin but could not differentiate between the two tumors. This case report adds to the rarity and morphologic heterogeneity of the group MPC.

Myopericytoma in the corpus cavernosum of the penis: A case report of a rare disease

Introduction

Myopericytomas usually occur in the extremities of older individuals; however, they also rarely occur in the penis. We report a case of myopericytoma in the corpus cavernosum of the penis and review the relevant literature.

Case presentation

A 76-year-old man presented with a slow-growing painless nodule on the left side of the penis. On physical examination, a non-tender, 7-mm mass was palpable. This tumor showed inhomogeneous low signal intensity on T2-weighted magnetic resonance imaging. The mass was excised and a myopericytoma diagnosed by pathological examination of the operative specimen.

Conclusion

We here report a rare case of myopericytoma in the corpus cavernosum of the penis. To the best of our knowledge, this is the second reported case of a myopericytoma in the penis and the first in the corpus cavernosum of the penis. Clinicians should keep this rare possibility in mind when investigating a mass in the penis.

PDGFRB and NOTCH3 Mutations are Detectable in a Wider Range of Pericytic Tumors, Including Myopericytomas, Angioleiomyomas, Glomus Tumors, and Their Combined Tumors

Pericytic tumors are subclassified as myopericytomas, myofibromas, angioleiomyomas, and glomus tumors according to the current World Health Organization classification. These pericytic tumors form a continuous morphologic spectrum, including those with combined morphology. However, to our knowledge, no widely accepted criteria for classifying tumors with combined morphology are available. Recent studies have identified platelet-derived growth factor receptor-beta (PDGFRB) gene mutations in a subset of myofibromas, myopericytomas, and myopericytomatoses but not in angioleiomyomas. NOTCH receptor 3 (NOTCH3) mutations have been reported in a subset of infantile myofibromatosis. To assess their potential role in classifying pericytic tumors, we investigated PDGFRB and NOTCH3 mutations in 41 pericytic tumors of variable morphology, including some combined forms. Our results show these mutations to be present in a variety of pericytic tumors, such as myopericytomas (PDGFRB, 3/11; NOTCH3, 4/11), myopericytomatoses (1/2; 1/2), myofibromas (3/6; 0/6), angioleiomyomas (2/13; 3/13), and glomus tumors (5/9; 1/9). Point mutations were identified in 3 tumors in PDGFRB exon 12 (Y562C, S574F, and G576S), 12 tumors in PDGFRB exon 14 (M655I, H657L, and N666K), and 9 tumors in NOTCH3 exon 25 (A1480S/T, D1481N, G1482S, T1490A, E1491K, G1494S, and V1512A). All PDGFRB mutations and NOTCH3 G1482S, T1490A, and G1494S mutations were classified as "deleterious/damaging" by ≥4 of 6 pathogenicity prediction tools in silico. Five-mutation-positive tumors, including 1 myopericytoma-angioleiomyoma, 2 myopericytomatoses-myofibroma, 1 myofibroma-myopericytoma and 1 angioleiomyoma-myopericytoma, were of combined morphology. Therefore, we found PDGFRB and NOTCH3 mutations to be detectable in a much wider variety of pericytic tumors than previously reported and confirmed myopericytomas, myofibromas, angioleiomyomas, and glomus tumors as members harboring PDGFRB or NOTCH3 mutations. Our results thus suggest that PDGFRB or NOTCH3 mutations are not useful for subclassifying members of the pericytic tumor family.

Primary hepatic myopericytoma coexisting with multiple cystic hepatic lesions: a case report

BACKGROUND

Hepatic myopericytoma (MPC) is an extremely rare pathological entity in the liver. Conversely, cystic hepatic lesions are a group of heterogeneous lesions encountered commonly in daily practice. Here, we report a unique case of the coexistence of primary hepatic MPC and multiple cystic hepatic lesions along with our perceptions on its diagnosis and treatment.

CASE PRESENTATION

A 56-year-old female patient was found to have a left liver mass during a routine physical examination. Computer tomography (CT) and magnetic resonance imaging (MRI) confirmed the existence of a left hepatic neoplasm along with multiple hepatic cysts but could not exclude the possible malignant nature of the neoplasm. Computer tomography (CT) also identified an enlarged mediastinal lymph node with a maximum diameter of 4.3 cm, which further underwent core needle biopsy under CT guidance. A histopathological examination was performed to rule out malignancy. Afterwards, the patient underwent left hemihepatectomy to resect a solid tumor of 5.5 cm × 5 cm × 4.7 cm with multiple cystic lesions which were histopathologically examined to establish the diagnosis of myopericytoma with hepatic cysts. Postoperatively, the patient recovered from the surgery quickly without significant adverse events and was not found to have a reoccurrence of the primary pathological entity.

CONCLUSIONS

This is the first reported case of a patient with the co-existence of primary hepatic myopericytoma and multiple cystic hepatic lesions undergoing surgical treatment with eventual recovery.

Primary intranasal perivascular wall tumors in 2 cats

Perivascular wall tumors (PWTs) are common well-known canine mesenchymal tumors. The term PWT has not yet been applied to cats; only 2 cases of feline soft tissue hemangiopericytomas (HEPs) are available. In human medicine, sinonasal HEP-like tumor/glomangiopericytoma (SHPCL/GP) and intranasal solitary fibrous tumor (SFT) are well-known mesenchymal tumors with staghorn vasculature and low malignant potential; however, these entities have not been described in small animals. We describe here the pathologic and immunohistochemical features of 2 cases of feline intranasal mesenchymal tumors consistent with PWTs and resembling human SHPCL/GP (case 1), and human intranasal SFT (case 2). Both cats developed intranasal, unilateral, polypoid, expansile neoplasms with a mostly patternless growth of spindle cells, minimal stroma, and prominent staghorn vessels. The stroma was PAS negative, which excludes a glomus tumor. Immunohistochemistry identified diffuse vimentin and PDGFRβ expression. Case 1 was α-SMA positive (as is human SHPCL/GP); case 2 was negative (as is human intranasal SFT). Both tumors were incompletely excised, leading to recurrence in case 1. Case 2 was lost to follow up. To our knowledge, intranasal PWTs have not been reported previously in cats. The frequency of the lesions is not known, but awareness of these entities may assist in their recognition and better characterization in the future.

Myopericytoma in the Antitragus of the Auricle: A Rare Tumor

A myopericytoma in the auricle is rare. If an auricle contains a large, firm, red-brown mass, excision should be considered because the mass may be a myopericytoma. After excision, histopathological and immunohistochemical diagnoses are essential to rule out malignancy. Long-term follow-up is required because the tumor is slow-growing.

Clinical and histopathological findings of a rare sinonasal glomangiopericytoma

Glomangiopericytoma is a rare vascular neoplasm of the nasal cavity and paranasal sinuses that occurs during the sixth or seventh decade of life. It is categorized as a borderline tumor with low malignant potential and classified as a distinct entity of sinonasal tumors with perivascular myoid phenotype by the World Health Organization (WHO). We report the case of a 50-year-old woman with nasal obstruction and severe epistaxis. The nasal sinuses computed tomography (CT), and magnetic resonance imaging (MRI) demonstrated a 3.1 cm soft tissue mass occupying the upper part of the left nasal cavity invading the left paranasal sinuses and nasal septum, and the left eye medial rectus muscle. A total mass resection was performed by nasal endoscopy. The histological and immunohistochemical examination yielded the diagnosis of glomangiopericytoma. This case report aims to contribute to the knowledge of nasal neoplasms. The need for more data on this entity is the main obstacle to developing standardized treatment guidelines.

Rare Case of Intravascular Myopericytoma-Imaging Characteristics and Review of the Literature

Myopericytoma is a rare vessel wall tumor, a subtype of hemangiopericytoma that usually develops subcutaneously. Intravascular myopericytoma is a rarer subtype, with only few cases reported in the literature and even fewer with imaging modalities included. We report the case of a 36-year-old man who was referred to our institution with a painless, palpable mass in the right arm and was evaluated with MRI, grey-scale and Doppler-mode ultrasound. Tumor histopathology and imaging characteristics are presented together with the role that each imaging modality played in the management of the patient.

A rapidly expanding nodule on the lower leg

We present a case of a 34-year-old man who developed a lesion over his posterior calf. We discuss the clinical and histopathological features, as well as relevant immunohistochemical markers.

Myopericytoma: A Review of Twenty-Three Cases Over Twelve Years and a Case Report of a Rare Neoplasm

Myopericytoma is a rare soft tissue tumor with a predilection for the distal extremities. It is commonly found in the skin and subcutaneous tissues and usually takes a benign course. Current knowledge is limited to isolated case series and reports; hence, this study aims to report our tertiary institution's experience with this uncommon entity. A review of our institution's pathology records for cases of myopericytoma was performed. From January 2009 to September 2020, 23 cases of myopericytoma were identified and their clinicopathologic features were reported. A unique case of myopericytoma of the ankle from the series was also highlighted as a case report. Among the 22 cutaneous cases, 18 were in the extremities and 4 in the head and neck. One patient had an intracranial lesion. Most patients developed asymptomatic nodules (72.2%), but 1 patient had a locally aggressive tumor on presentation. None recurred despite marginal excision in some patients (80.0%). In conclusion, pathologists and surgeons who encounter this rare neoplasm can reassure patients of its benign tendency.

Intravascular Myopericytoma: A Case Report

Myopericytoma is a rare tumor that arises from perivascular myoid cells. Intravascular myopericytoma is an exceptionally rare subtype with a small number of cases reported. Here, we describe the case of a 31-year-old woman who presented with a lump on the dorsum of the right foot for nine months. Imaging indicated that the lesion is in close proximity to the dorsalis pedis vessels. Following surgical excision, the histological analysis revealed a benign neoplasm arising within a vein wall with features of vascular and pericytic differentiation. When using immunohistochemistry, the blood vessels were highlighted by the cluster of differentiation (CD) 31 and smooth muscle actin (SMA) with negative staining for pancytokeratins. These features led to the diagnosis of intravascular myopericytoma.

Thoracic myopericytoma in an older adult, rare but possible: A case report

Myopericytoma is a rare tumor generally arising from skin and soft tissues of extremities, trunk, head, and neck regions, rarely from visceral sites. An intrathoracic visceral localization may carry a broad differential diagnosis including primary lung, pleura and chest wall lesions, or metastatic lesions. To date, any radiological features have been recognized and diagnosis of myopericytoma with intrathoracic localization remains still challenging. Here, we describe the case of a subpleural lesion incidentally diagnosed in an older adult affected by gastric cancer. Radiological features did not allow a differential diagnosis between a benign lesion, a primary tumor, or a metastasis. After resection, the histological examination showed histopathological features congruent with the diagnosis of myopericytoma. This unusual presentation reflects the need to share clinical, radiological, and histopathological data about this uncommon but frequently misdiagnosed disease.

Pontine Myopericytoma: Case Report and Literature Review

Myopericytoma (MPC) is a benign soft tissue tumor that develops from perivascular myoid cells and is part of the perivascular tumor group. MPC most commonly occurs in the subcutaneous soft tissues of the extremities, while intracranial MPC is remarkably rare. Herein, we report the case of a 45-year-old woman with myopericytoma who had a 2-week history of recurrent dizziness. Magnetic resonance imaging (MRI) revealed an irregular mass in the pons, with nodular enhancement of the mass on contrast-enhanced scans. The mass was considered a vascular lesion and was highly suspected to be a hemangioblastoma, prompting surgical intervention for the patient. The postoperative pathological report corrected the initial diagnosis, hemangioblastoma, to MPC. Intracranial MPC is extremely rare and there are no detailed imaging sources for this condition; furthermore, MPC occurrence in the pons has not been reported previously. This report presents the etiological characteristics intracranial MPC as visualized through MRI data alongside a comparative discussion on other reported diagnoses that resemble MPC. The case findings will provide a more widespread understanding for radiologists regarding the differential diagnosis of intracranial blood-rich supply lesions.

Epstein-Barr virus-associated intracranial myopericytoma in a child: case report and review of literature

BACKGROUND

Myopericytomas are benign soft tissue tumors which are rarely found as intracranial masses.

METHODS

A review of SCOPUS and PubMed databases for case reports and case series was done for patients with intracranial myopericytomas. Data on demographics, clinical features, imaging, surgical management employed, and outcomes were collected.

RESULTS

We found a total of 9 cases in the literature and we describe an additional case from our own experience. The mean age at presentation was 50.1 years (32-64 years), with a female predominance. Most tumors were in the posterior fossa and were multifocal in AIDS patients. The most common clinical manifestations were visual disturbances, headaches, and vomiting. An association with EBV was reported in two cases and was also found in our own case. Gross total excision and even subtotal excision were definitive therapies with no recurrences reported with a mean follow-up of 22.7 months. Our case is the first EBV-associated intracranial myopericytoma in a child.

CONCLUSION

Intracranial myopericytomas are rare; some have an association with EBV and immunodeficient states. Surgery is the only necessary treatment and outcomes are generally favorable for these benign neoplasms.

Pre-tibial myopericytoma: a case report

Myopericytoma (MPC) is a rare, benign tumour often presenting as a cutaneous growth commonly in the lower extremities. It is distinguished by its concentric layering of spindle shaped myoid appearing cells perivascularly. These cells diagnostically stain positive to alpha smooth-muscle actin and rarely positive to desmin stain. This case study reviews the presentation of a 56-year-old male with a slow-growing, pre-tibial lesion developing over a 7–8 year period. This lesion was asymptomatic and demonstrated vascular involvement on ultrasound scan. This lesion measured 19 × 15 × 9 mm histologically and contained bland spindle cells surrounding vessels that interestingly stained positive to both alpha smooth-muscle actin and desmin. The histological findings in correlation to clinical presentation and imaging led to a diagnosis of MPC.

Ankle Myopericytoma: A Rare Case Report and Cytogenetic Study

Myopericytoma (MPC) is an uncommon benign neoplasm of the skin and soft tissues belonging to a spectrum of tumors that are histologically recognized by their distinctive perivascular myoid cell differentiation. These distinct tumors are more prevalent among middle-aged males, and they arise more frequently in the subcutaneous tissue of the four extremities. In this paper, myopericytoma is reported in a 59-year-old Saudi male, presented with a painless small cyst involving the left ankle suspected clinically to be a ganglion cyst. Following surgical excision of the cyst, the diagnosis of myopericytoma was made based on the histopathological pattern of the disease. This paper focuses on the clinical and histopathological findings of myopericytoma and emphasizes the importance of immunohistochemistry as well as molecular testing in reaching the final diagnosis.

A retroperitoneal myopericytoma: The first case located at the retroperitoneal area and not originate from the kidneys

A 25-year-old woman had a mass of approximately 65 cm × 33 cm × 102 cm, located in the left paraaortic area on CT scan. It was diagnosed as retroperitoneal malignant neoplasm on imaging. Afterward, open retroperitoneal tumor excision was performed. At laparotomy, the mass was carefully dissected from the ureter, renal artery, and aorta and excised as en-bloc. The pathological result was "myopericytoma." Histologically, the pathological findings characterized a pericytic neoplasm characterized by a perivascular growth of myoid tumor cells. In addition, there were uniform, oval-shaped cells with eosinophilic cytoplasm arranged in short fascicles around blood vessels. The cytologic atypia and mitoses were absent. There are many different tumors in the retroperitoneal area. Most of these lesions are malign nature. Nevertheless, for each benign and malign neoplasm, the preoperative imaging method is generally similar. This present case showed the significant findings of myopericytoma, a benign pathology located in the retroperitoneal area.

Myopericytoma of the Parotid and Molecular Profiling: Report of a Rare Case and Review of the Literature

Myopericytomas are uncommon tumors defined by their round to spindle shaped cells often arranged in a concentric pattern of perivascular growth. They are typically well-circumscribed, nodular, slow-growing lesions that occur in the soft tissue of the extremities. Here, we present a 30-year-old female with a 2.4 cm myopericytoma occurring in the deep lobe of the parotid gland. The diagnosis was made with detailed histopathologic and immunohistochemical findings and positive identification of the specific mutation for PDGFRβ p.Asp666Lys by next generation sequencing (NGS). This is the first case report of a parotid myopericytoma with a genetic testing that shows a particular mutation that has been linked to myopericytomatosis.

Exophytic Nodule on the Finger

Myopericytoma is a rare, benign growth characterized by painless lesions with a predilection for the extremities, although they may be found in or on any part of the body. These tumors typically present as a rounded or dome-like non-exophytic lesion and exhibit a benign disease course. Treatment is generally reserved for cosmetic or functional purposes. We present a case of an atypical presentation of an exophytic digital myopericytoma in a 45-year-old female treated with local punch excision.

Myopericytoma Involving Proximal Phalanx of Index Finger: Masquerading as Tenosynovial Giant Cell Tumor - A Case Report

Introduction

Myopericytoma (MPC) is an uncommon benign smooth muscle cell neoplasm which frequently arises in lower extremities, sparsely they can be found in upper extremities and head and neck region. Very few case reports are available in the literature documenting hand localization of this tumor.

Case Presentation

In this report, we present a case of 83-year-old male individual with a mass lesion on the proximal phalanx of index finger of the right hand. Recent trivial trauma led the patient to medical assistance. Imaging mimicked Giant cell tumor of tendon sheath due to site of the lesion. The lesion was excised surgically. The final diagnosis of the specimen confirmed by histopathology was MPC, a benign smooth-muscle cell neoplasm.

Conclusion

MPC is a rare entity; however, definitive diagnosis is often challenging because it mimics some malignant soft-tissue neoplasms. A multidisciplinary approach is required to identify this lesion as being benign and thus define the correct modality of treatment.

Fast growing myopericytoma of the hand: Case report and literature review

Introduction and importance

Myopericytoma (MPC) is a rare benign soft tissue neoplasm that arises from perivascular smooth muscle-like myoid cells that share features of both glomus and smooth muscle cells. It usually slow growing solitary tumor that might mimic aggressive sarcoma.

Case presentation

45 years old male, with unremarkable medical history, presented with fast growing mass on the left 1st webspace that was noticed 6 months prior to presentation. Investigations with US and MRI showed highly vascular solid mass that was worrisome for malignant lesion. Surgical excision was done and histopathology confirmed the diagnosis of myopericytoma.

Clinical discussion

MPC is a rare perivascular neoplasm that’s reported mainly in the extremities with lower limbs are most affected sites. Usually it presents as solid painless slowly growing mass. However, Multiple papers reported different rare presentations like multiple, painful and some with malignant transformation.

Conclusion

MPC is a benign tumor that might mimic aggressive sarcoma. Such cases should be approached with high suspicion and proper investigation and management should be followed promptly.

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Myopericytoma (MPC) is a rare benign soft tissue neoplasm.

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It usually slow growing solitary tumor that might mimic aggressive sarcoma.

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It occurs mainly in the extremities with lower limbs are most affected sites.

•

High suspicion and proper investigation and management to achieve proper diagnosis

Imaging features of myopericytoma arising from the parotid gland: Report of 2 cases and literature review

RATIONALE

Myopericytoma of the parotid gland is a rare condition of which preoperative definitive diagnosis is relatively challenging. The purpose of this case report is to highlight the radiologic features of myopericytoma of parotid gland.

PATIENT CONCERNS

A 62-year-old man presented with a history of a walnut-size mass in left parotid gland when yawned for half-month, and a 48-year-old woman complaint about a grape-size, painless mass behind the right ear for a month.

DIAGNOSES

Radiological examinations suggested that both lesions were cyst-solid mixed lesions with relatively smoothed margins, with or without significant enhancement while the lesion without enhancement had a hemorrhage. Then a diagnosis of benign tumor arising from the parotid gland was made. Final diagnosis of myopericytoma was confirmed by histopathological and immunohistochemical examinations after surgical resection.

INTERVENTIONS

Both patients underwent excision of the tumor and the superficial parotidectomy with facial nerve preservation.

OUTCOMES

Both patients recovered without any intraoperative or postoperative complication and had no signs of recurrence during a 17-month and 5-year follow-up.

LESSONS

Parotid gland myopericytoma is an exceedingly rare tumor which diagnosis can be challenging, and this is the first published report specifying the magnetic resonance features of the disease.

Oral myopericytoma: a rare pediatric case report and a review of the literature

Background

Myopericytoma is a rare mesenchymal neoplasm with perivascular myoid differentiation that arises most commonly in middle adulthood. The lesion generally involves the subcutaneous tissue of distal extremities. Myopericytoma of the oral cavity is extremely rare. Herein we report a case of oral myopericytoma in a pediatric patient, who was treated via a conservative approach with a follow up of 8 years. The case is followed by a literature review. To our knowledge this is the first documented case of oral myopericytoma affecting a patient of such a young age.

Case presentation

A 6 years old boy was referred to the maxillofacial surgery department for the evaluation of a solitary growth of the right maxillary buccal and palatal gingiva. Histology and immunohistochemistry confirmed the diagnosis of myopericytoma.

Conclusions

Our patient was treated by local excision with no recurrence in 8 years of follow up. Conservative approach should be considered for the treatment oral myopericytoma especially in young patients in tooth bearing areas.

Rare Diseases of the Nose, the Paranasal Sinuses, and the Anterior Skull Base

Due to their low incidence and thus resulting limited diagnostic criteria as well as therapeutic options, rare diseases of the nose, the paranasal sinuses, and the anterior skull base are a significant challenge. The value as of which a disease has to be considered as rare amounts to a maximum of 5 patients per 10 000 people. Within these diseases, however, there are extreme differences. Some rare or orphan diseases like for example the inverted papilloma belong to regularly diagnosed and treated diseases of larger departments of oto-rhino-laryngology whereas other rare diseases and malformations have only been described in less than 100 case reports worldwide. This fact emphasizes the necessity of bundling the available experience of diagnostics and therapy. The present article gives an overview about rare diseases of the nose, the paranasal sinuses, and the anterior skull base from the field of diseases/syndromes of the olfactory system, malformations of the nose and paranasal sinuses, ventilation and functional disorders as well as benign and malignant tumors. The classification and data on diagnostic and therapeutic options were established based on the current literature.

Orbital myopericytoma: an unusual tumor in an unusual location

A 71-year-old male with a 4-month history of bulging, tearing, and redness in the right eye presented with vision loss, proptosis, conjunctival hyperemia, and chemosis. Magnetic resonance imaging showed a right intraconal solid mass with extraconal extension, hyper-intense in T2 sequences with heterogeneous contrast enhancement. Complete excision of the mass was performed through a lateral orbitotomy. Histological analysis revealed a neoplasm with high vessel density, solid growth of oval cells, a concentric proliferation of the wall of small vessels, and a weak and patchy positivity for smooth muscle actin. These findings were consistent with the diagnosis of myopericytoma. After surgery, visual acuity improved in the affected eye and after 18 months of follow-up there have been no signs of recurrence.

Myopericytoma-like tumors of the lung: Report of two cases

Myopericytoma is a benign neoplasm presenting cells with different shapes, from oval to spindle, and myoid showing with perivascular growth, which frequently originates from the skin and soft tissues of distal extremities, trunk, head, and neck regions. These tumors rarely have been reported to occur in visceral sites. There is only one case of myopericytoma showing pulmonary involvement with multiple nodules. Although most myopericytomas behave in a benign manner, some cases of malignant myopericytoma arising in both superficial soft tissue and visceral locations have been described. We describe two cases of pulmonary tumors with myopericytoma-like features.

Imaging features of myopericytoma of the breast: A case report and review of the literature

Myopericytoma is a rare perivascular tumor commonly arising in the superficial soft tissue and subcutaneous tissue of the distal extremities. We report the first case of myopericytoma occurring in the breast, focusing on the imaging and histopathological characteristics of the tumor. From an imaging perspective, myopericytoma presents a well-circumscribed, marked hypervascularity, and intense enhancement after injection of contrast material. Imaging examinations, such as ultrasonography and magnetic resonance imaging, can contribute to the detection of tumor invasion to adjacent structures or distant metastases, and provide evidence for a treatment plan.

Imaging performance and preoperative differential diagnosis of multiple myopericytoma in the liver: A case report

Myopericytoma is a rare type of benign tumor, which commonly affects all four limbs. The occurrence of myopericytoma in the liver is extremely rare. Myopericytoma with a size of >1 cm in diameter in the liver has not been previously reported. Due to the limited number of cases, the preoperative diagnosis of liver myopericytoma based on laboratory and imaging examinations is difficult. In the present case report, a patient with multiple myopericytoma in the liver, with a maximum diameter of 4.5 cm was described, with accompanying computed tomography (CT) and positron emission tomography/CT (PET/CT) imaging profiles. The aim of the present report was to discuss the preoperative differential diagnosis between myopericytoma and other common liver neoplasms, such as intrahepatic cholangiocarcinoma or liver metastasis.

Myopericytoma arising from myopericytosis-a hitherto unrecognized entity within the lung

Two cases of myopericytosis combined with pericytoma originating within the lung are reported. These are rare pulmonary tumors. The differential diagnosis for hemangiopericytoma and pericytic tumors with glomus elements is discussed. Both myopericytic lesions mimic other lesions, which are more commonly seen in the lung. Based on the expression of vascular growth factor receptors 2 and 3, an antiangiogenic therapy was suggested for the patient with the myopericytoma. A treatment with an angiogenesis inhibitor resulted in a regression of the tumor, but not the precursor lesion. Probably a more specific therapy using tyrosine kinase inhibitors for VEGFR2/3 might better control these myopericytic proliferations.

Radiopathological correlations of myopericytomas of the hand: emphasis on the MRI perivascular pushing growth pattern

Myopericytomas are exceedingly rare soft-tissue tumors with less than 10 cases including radiological depictions. We report three new cases of benign myopericytomas located in the soft-tissues of the hand in adult patients. A pre-treatment MRI was available for all patients and systematically evidenced well-defined, lobulated tumors closely related to the superficial palmar vascular arch and/or digital vessels with a perivascular pushing growth pattern that correlated with pathological findings. Though rare, this small case series show that myopericytomas display recurrent imaging features that could support their radiological diagnosis.

Gingival ossifying myopericytoma in a pediatric patient: Immunohistochemical analysis and literature review

Myopericytoma is a rare mesenchymal tumor characterized by a hemangiopericytoma-like vascular pattern with perivascular myoid differentiation. To date, only 11 cases of oral myopericytoma have been reported. To the best of our knowledge, myopericytoma with gingival involvement and associated with calcifications has not been reported, expanding their clinicopathological spectrum. Herein, we report a 12-year-old girl female patient who presented a gingival nodule diagnosed as ossifying myopericytoma, which should be considered in the differential diagnosis when assessing oral soft tissue lesions, especially in pediatric patients.